Rev. 1.0, 09/01, page 292 of 904
7.5.8
Basic Bus Cycles
An example of the basic DMAC bus cycle timing is shown in figure 7.17. In this example, word-
size transfer is performed from 16-bit, 2-state access space to 8-bit, 3-state access space. When
the bus is transferred from the CPU to the DMAC, a source address read and destination address
write are performed. The bus is not released in response to another bus request, etc., between
these read and write operations. As like CPU cycles, DMA cycles conform to the bus controller
settings.
The address is not output to the external address bus in an access to on-chip memory or an internal
I/O register.
ø
Address bus
DMAC cycle (1-word transfer)
Source
address
Destination address
CPU cycle
CPU cycle
T
1
T
2
T
3
T
1
T
2
T
3
T
1
T
2
Figure 7.17 Example of DMA Transfer Bus Timing
7.5.9
DMA Transfer (Dual Address Mode) Bus Cycles
Short Address Mode: Figure 7.18 shows a transfer example in which
7(1'
output is enabled
and byte-size short address mode transfer (sequential/idle/repeat mode) is performed from external
8-bit, 2-state access space to internal I/O space.
Summary of Contents for H8S/2376 F-ZTAT
Page 24: ...Rev 1 0 09 01 page xxiv of xliv ...
Page 38: ...Rev 1 0 09 01 page xxxviii of xliv ...
Page 44: ...Rev 1 0 09 01 page xliv of xliv ...
Page 60: ...Rev 1 0 09 01 page 16 of 904 ...
Page 96: ...Rev 1 0 09 01 page 52 of 904 ...
Page 116: ...Rev 1 0 09 01 page 72 of 904 ...
Page 148: ...Rev 1 0 09 01 page 104 of 904 ...
Page 284: ...Rev 1 0 09 01 page 240 of 904 ...
Page 422: ...Rev 1 0 09 01 page 378 of 904 ...
Page 634: ...Rev 1 0 09 01 page 590 of 904 ...
Page 656: ...Rev 1 0 09 01 page 612 of 904 ...
Page 668: ...Rev 1 0 09 01 page 624 of 904 ...
Page 780: ...Rev 1 0 09 01 page 736 of 904 ...
Page 796: ...Rev 1 0 09 01 page 752 of 904 ...
Page 806: ...Rev 1 0 09 01 page 762 of 903 ...
Page 808: ...Rev 1 0 09 01 page 764 of 904 ...
Page 921: ...Rev 1 0 09 01 page 877 of 904 ø tBRQOD tBRQOD Figure 24 24 External Bus Request Output Timing ...
Page 938: ...Rev 1 0 09 01 page 894 of 904 ...